Edit: We're reading below that lots of regions outside the UK are being charged a really very much larger sum. Which sucks. Valve will always insist prices are decided by publishers, so yell at Warner. There's also confusion over the inclusion of Arkham City and War In The North - to be absolutely clear, the Warner Complete Pack definitely currently includes those games, whether by design or mistake. It also seems that some regions can't see the deal at all. The solution: move to the UK.
I'm never quite sure whether posting about the Steam sale is doing mindless promotion for the company, or alerting our readers to amazing prices for games. I'm going with the latter in this instance, because bloody hell, this one took me by surprise. Not boasted of on the front page of Steam's decidedly confusing sales page (not including the names of the games on sale is perhaps an odd choice) is the Warner Complete Pack. Clearly one of many extraordinarily reduced bundles (19 THQ games for £50, 80 Sega games for £70 for instance), the Warner bundle brings 18 games for £40, and one of them is Batman: Arkham City. So that's basically "buy Arkham City, get every other Warner game on Steam free." And one of those is Bastion. And another is the brand new Lord Of The Rings: War In The North. And of course yet another is Batman: Arkham Asylum.
So here's the complete list of what you get for the price of one game:
Batman: Arkham City
Arkham City's Nightwing and Robin bundles
Batman: Arkham Asylum GOTY
F.E.A.R. 2: Project Origin, plus Reborn DLC
F.E.A.R.s Extraction Point and Perseus Mandate
LEGO Harry Potter: Years 1-4
Lord Of The Rings: War In The North
Watchmen: The End Is Nigh 1 and 2
Unreduced that lot would cost you £272.32 on Valve's store. So, I'm going to venture that forty quid is a reasonably decent offer.